1. Field of the Invention
The present invention relates to an apparatus for and a method of supplying cold air in a refrigerator, and more particularly to an apparatus for and a method of concentratedly supplying cold air to a temperature-increasing portion of the interior of a refrigerator, based on internal temperatures of the refrigerator at respective portions of the interior of the refrigerator.
2. Description of the Prior Art
FIGS. 1 and 2 illustrate the configuration of a general refrigerator and a general cold air supply configuration applied to the refrigerator configuration, respectively.
As shown in FIGS. 1 and 2, the interior of the refrigerator is divided into a refrigerating compartment 10 and a freezing compartment 30 by a barrier 20. An evaporator 32 is disposed in the rear of the freezing compartment 30. A refrigerant of low temperature and low pressure passes through the evaporator 32. In the rear of the freezing compartment 30, a fan 34 is also disposed near the evaporator to circulate cold air. A refrigerating compartment duct 12 is provided at one side wall of the refrigerating compartment 10 to supply heat-exchanged cold air from the evaporator to the refrigerating compartment 10. A plurality of cold air outlets 12a, 12b and 12c are formed in the refrigerating compartment duct 12. Return ducts 22 and 24 are provided at the barrier 20 to return air of relatively high temperature circulating through the refrigerating and freezing compartments 10 and 30 to the evaporator 32.
Now, the circulation of cold air in the above-mentioned refrigerator will be described. When an internal refrigerating cycle of the refrigerator operates, a refrigerant of low temperature and low pressure passes through the evaporator 32. The refrigerant absorbs heat around the evaporator 32 while passing through the evaporator 32, thereby causing it to be evaporated. As a result, air contacting the evaporator 32 is cooled to a relatively low temperature. The cold air around the evaporator 32 is partially supplied to the freezing compartment 30 and partially supplied to the refrigerating compartment 10 by the fan 34.
The supply of the cold air to the refrigerating compartment 10 is carried out via cold air passages formed in the barrier 20, the refrigerating compartment duct 12, and the cold air outlets 12a, 12b and 12c formed in the refrigerating compartment duct 12.
Meanwhile, a cold air damper 14 is disposed at the upper portion of the refrigerating compartment duct 12 to control the supply of cold air. The cold air damper 14 controls the amount of cold air supplied to the refrigerating compartment duct 12, based on an internal temperature of the refrigerating compartment 10 sensed by a refrigerating compartment temperature sensor 15 installed in the refrigerating compartment 10.
The cold air supplied to the refrigerating compartment 10 via the above-mentioned supply path carries out a heat exchange with foods stored in the refrigerating compartment 10 while circulating in the interior of the refrigerating compartment 10. As a result, the cold air warms to a relatively high temperature. The warm air of relatively high temperature then returns to the evaporator 32 via the refrigerating compartment return duct 24 having an inlet at the lower surface of the barrier 20. The warm air carries out a heat exchange with the evaporator 32, so that it is cooled to a relatively low temperature. As the above-mentioned circulation of cold air is repeatedly carried out, the refrigerating compartment is maintained at a predetermined temperature.
Cold air is also supplied to the freezing compartment 30. After the cold air supplied to the freezing compartment 30 circulates the interior of the freezing compartment 30, it returns to the evaporator 32 via the freezing compartment return duct 22 formed in the barrier 20. This circulation of cold air is repeatedly carried out.
The above-mentioned circulation of cold air is achieved by the operation of the refrigerator, namely, the driving of the refrigerating cycle. The driving of the refrigerating cycle is carried out, based on the current temperature of the refrigerating compartment 10 or freezing compartment 30. That is, when the current of the refrigerating compartment 10 or freezing compartment 30 is higher than a predetermined temperature, the refrigerator operates. However, since the refrigerating compartment 10 and freezing compartment 30 have different temperatures set for the operation of the refrigerator, the operation of the refrigerator is carried out in different manners respectively based on the differently set temperatures.
Where the operation of the refrigerator is determined on the basis of the temperature of the freezing compartment 30, it is determined whether or not the current temperature of the freezing compartment 30 sensed by a freezing compartment temperature sensor 36 installed in the interior of the freezing compartment 30 is higher than a predetermined temperature (for example, -18.degree. C.) set in association with the freezing compartment 30. When the current temperature of the freezing compartment 30 is higher than the predetermined temperature, the operation of the refrigerator is begun. When the current temperature of the freezing compartment 30 is not higher than the predetermined temperature, the operation of the refrigerator is stopped. That is, the operation of the refrigerator is carried out irrespective of the temperature of the refrigerating compartment 10. In this case, the supply of cold air to the refrigerating compartment 10 is controlled by the opening and closing of the refrigerating compartment duct 12 carried out by the cold air damper 14 based on a temperature sensed by the refrigerating compartment temperature sensor 15.
Where the operation of the refrigerator is determined on the basis of the temperature of the refrigerating compartment 10, it is determined whether or not the current temperature of the refrigerating compartment 10 sensed by the refrigerating compartment temperature sensor 15 installed in the interior of the freezing compartment 30 is higher than a predetermined temperature set in association with the refrigerating compartment 10. When the current temperature of the refrigerating compartment 10 is higher than the predetermined temperature, the operation of the refrigerator is begun. When the current temperature of the refrigerating compartment 10 is not higher than the predetermined temperature, the operation of the refrigerator is stopped. That is, the operation of the refrigerator is carried out irrespective of the temperature of the freezing compartment 30.
In the case wherein the operation of the refrigerator is determined on the basis of the temperature of the freezing compartment 30, the supply of cold air may not be carried out even when the current temperature of the refrigerating compartment 10 is higher than the predetermined temperature set in association with the refrigerating compartment 10.
This is because the operation of the refrigerator is determined irrespective of the current temperature of the refrigerating compartment 10. In this case, there is a problem in that it is difficult to maintain the refrigerating compartment 10 in a fresh state.
In the case wherein the operation of the refrigerator is determined on the basis of the temperature of the refrigerating compartment 10, the amount of cold air supplied to the freezing compartment 30 may be insufficient because the predetermined temperature set in association with the refrigerating compartment 10 is relatively high (for example, 3.degree. C.).
As mentioned above, the refrigerating compartment temperature sensor 15 installed in the interior of the refrigerating compartment 10 is used in the case of controlling the supply of cold air based on the current temperature of the refrigerating compartment 10 in order to sense the current temperature of the refrigerating compartment 10. However, it is difficult to sense temperatures of all portions of the refrigerating compartment 10 because the refrigerating compartment temperature sensor 15 is fixed to a selected portion of the refrigerating compartment 10. In other words, the refrigerating compartment temperature sensor 15 can not sense an increase in temperature occurring at a portion of the refrigerating compartment 10 spaced apart from the place where the temperature sensor 15 is disposed. As a result, there is a problem in that a local temperature increase may occur in the refrigerating compartment 10.
In the above-mentioned refrigerator configuration, the total amount of cold air introduced into the refrigerating compartment 10 via the refrigerating compartment duct 12, and the distribution ratio of cold air in different portions of the refrigerating compartment 10, namely, the ratio among the amounts of cold air respectively discharged into different portions of the refrigerating compartment 10 via the cold air outlets 12a, 12b and 12c of the refrigerating compartment duct 12, are fixed upon designing the refrigerator. For this reason, it is impossible to achieve a positive supply of cold air coping with the storage of a new load.
Consequently, it is difficult to achieve an accurate supply of cold air based on a temperature deviation in the refrigerating compartment in the above-mentioned case wherein the supply of cold air is controlled on the basis of the temperature of the refrigerating compartment. Furthermore, the amount of cold air supplied to each portion of the refrigerating compartment is fixed by the associated cold air outlet formed in the refrigerating compartment duct. In other words, each portion of the refrigerating compartment is supplied with a set, constant amount of cold air, irrespective of whether or not a new load is stored in the refrigerating compartment portion.